dsp rework: implement 64 bit ticks no seconds

2 files changed, 23 insertions, 69 deletions

diff --git a/usrp2/timing/time_64bit.v b/usrp2/timing/time_64bit.v
index 03df07108..6f335890e 100644
--- a/usrp2/timing/time_64bit.v
+++ b/usrp2/timing/time_64bit.v
@@ -1,5 +1,5 @@
 //
-// Copyright 2011 Ettus Research LLC
+// Copyright 2011-2012 Ettus Research LLC
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -18,7 +18,7 @@
 
 
 module time_64bit
-  #(parameter TICKS_PER_SEC = 32'd100000000,
+  #(
     parameter BASE = 0)
    (input clk, input rst,
     input set_stb, input [7:0] set_addr, input [31:0] set_data,  
@@ -31,23 +31,20 @@ module time_64bit
     output [31:0] debug
     );
    
-   localparam 	   NEXT_SECS = 0;   
-   localparam 	   NEXT_TICKS = 1;
+   localparam 	   NEXT_TICKS_HI = 0;
+   localparam 	   NEXT_TICKS_LO = 1;
    localparam      PPS_POLSRC = 2;
    localparam      PPS_IMM = 3;
-   localparam      TPS = 4;
    localparam      MIMO_SYNC = 5;
    
-   reg [31:0] 	   seconds, ticks;
-   wire 	   end_of_second;
+   reg [63:0] 	   ticks;
 
    always @(posedge clk)
-     vita_time <= {seconds,ticks};
+     vita_time <= ticks;
    
    wire [63:0] 	   vita_time_rcvd;
    
-   wire [31:0] 	   next_ticks_preset, next_seconds_preset;
-   wire [31:0] 	   ticks_per_sec_reg;
+   wire [63:0] 	   next_ticks_preset;
    wire 	   set_on_pps_trig;
    reg 		   set_on_next_pps;
    wire 	   pps_polarity, pps_source, set_imm;
@@ -57,18 +54,18 @@ module time_64bit
 
    reg [15:0] 	   sync_counter;
    wire 	   sync_rcvd;
-   wire [31:0] 	   mimo_secs, mimo_ticks;
+   wire [63:0] 	   mimo_ticks;
    wire 	   mimo_sync_now;
    wire 	   mimo_sync;
    wire [7:0] 	   sync_delay;
    
-   setting_reg #(.my_addr(BASE+NEXT_TICKS)) sr_next_ticks
+   setting_reg #(.my_addr(BASE+NEXT_TICKS_LO)) sr_next_ticks_lo
      (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
-      .in(set_data),.out(next_ticks_preset),.changed());
+      .in(set_data),.out(next_ticks_preset[31:0]),.changed());
    
-   setting_reg #(.my_addr(BASE+NEXT_SECS)) sr_next_secs
+   setting_reg #(.my_addr(BASE+NEXT_TICKS_HI)) sr_next_ticks_hi
      (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
-      .in(set_data),.out(next_seconds_preset),.changed(set_on_pps_trig));
+      .in(set_data),.out(next_ticks_preset[63:32]),.changed(set_on_pps_trig));
 
    setting_reg #(.my_addr(BASE+PPS_POLSRC), .width(2)) sr_pps_polsrc
      (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
@@ -78,10 +75,6 @@ module time_64bit
      (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
       .in(set_data),.out(set_imm),.changed());
 
-   setting_reg #(.my_addr(BASE+TPS), .at_reset(TICKS_PER_SEC)) sr_tps
-     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
-      .in(set_data),.out(ticks_per_sec_reg),.changed());
-
    setting_reg #(.my_addr(BASE+MIMO_SYNC), .at_reset(0), .width(9)) sr_mimosync
      (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
       .in(set_data),.out({mimo_sync,sync_delay}),.changed());
@@ -110,29 +103,21 @@ module time_64bit
      else if(set_imm | pps_edge)
        set_on_next_pps <= 0;
 
-   wire [31:0] 	   ticks_plus_one = ticks + 1;
+   wire [63:0] 	   ticks_plus_one = ticks + 1;
    
    always @(posedge clk)
      if(rst)
        begin
-	  seconds <= 32'd0;
-	  ticks <= 32'd0;
+	  ticks <= 64'd0;
        end
      else if((set_imm | pps_edge) & set_on_next_pps)
        begin
-	  seconds <= next_seconds_preset;
 	  ticks <= next_ticks_preset;
        end
      else if(mimo_sync_now)
        begin
-	  seconds <= mimo_secs;
 	  ticks <= mimo_ticks;
        end
-     else if(ticks_plus_one == ticks_per_sec_reg)
-       begin
-	  seconds <= seconds + 1;
-	  ticks <= 0;
-       end
      else
        ticks <= ticks_plus_one;
 
@@ -162,9 +147,8 @@ module time_64bit
       .sync_rcvd(sync_rcvd),
       .exp_time_in(exp_time_in) );
 
-   assign mimo_secs = vita_time_rcvd[63:32];
-   assign mimo_ticks = vita_time_rcvd[31:0] + {16'd0,sync_delay};
-   assign mimo_sync_now = mimo_sync & sync_rcvd & (mimo_ticks <= TICKS_PER_SEC);
+   assign mimo_ticks = vita_time_rcvd[63:0] + {48'd0,sync_delay};
+   assign mimo_sync_now = mimo_sync & sync_rcvd;
 
    assign debug = { { 24'b0} ,
 		    { 2'b0, exp_time_in, exp_time_out, mimo_sync, mimo_sync_now, sync_rcvd, send_sync} };
diff --git a/usrp2/timing/time_compare.v b/usrp2/timing/time_compare.v
index 54ea000d6..21607f51c 100644
--- a/usrp2/timing/time_compare.v
+++ b/usrp2/timing/time_compare.v
@@ -1,5 +1,5 @@
 //
-// Copyright 2011 Ettus Research LLC
+// Copyright 2011-2012 Ettus Research LLC
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -16,49 +16,19 @@
 //
 
 
-// Top 32 bits are integer seconds, bottom 32 are clock ticks within a second
+// 64 bits worth of ticks
 
 module time_compare
   (input [63:0] time_now,
    input [63:0] trigger_time,
    output now,
    output early,
-   output late, 
+   output late,
    output too_early);
-   
-   wire    sec_match   = (time_now[63:32] == trigger_time[63:32]);
-   wire    sec_late    = (time_now[63:32] > trigger_time[63:32]);
 
-   wire    tick_match  = (time_now[31:0] == trigger_time[31:0]);
-   wire    tick_late   = (time_now[31:0] > trigger_time[31:0]);
-/*   
-   assign now 	       = sec_match & tick_match;
-   assign late 	       = sec_late | (sec_match & tick_late);
-   assign early        = ~now & ~late;
-*/
+    assign now = time_now == trigger_time;
+    assign late = time_now > trigger_time;
+    assign early = ~now & ~late;
+    assign too_early = 0; //not implemented
 
-   /*
-   assign now = (time_now == trigger_time);
-   assign late = (time_now > trigger_time);
-   assign early = (time_now < trigger_time);
-   */
-
-   // Compare fewer bits instead of 64 to speed up logic
-   // Unused bits are not significant
-   //     Top bit of seconds would put us in year 2038, long after
-   //        the warranty has run out :)
-   //     Top 5 bits of ticks are always zero for clocks less than 134MHz
-   //     "late" can drop bottom few bits of ticks, and just delay signaling
-   //        of late.  
-   //     "now" cannot drop those bits, it needs to be exact.
-   
-   wire [57:0] short_now = {time_now[62:32],time_now[26:0]};
-   wire [57:0] short_trig = {trigger_time[62:32],trigger_time[26:0]};
-
-   assign now = (short_now == short_trig);
-   assign late = (short_now[57:5] > short_trig[57:5]);
-   assign early = (short_now < short_trig);
-   
-   assign too_early    = (trigger_time[63:32] > (time_now[63:32] + 4));  // Don't wait too long
-   
 endmodule // time_compare